Evaluation of neutron properties from (g, n) reactions in the laser-driven ion accelerator

Sakaki, Hironao; Fukuda, Yuji; Kanasaki, Masato; Nishiuchi, Mamiko; Jinno, Satoshi   ; Yogo, Akifumi; Fukami, Tomoyo; Kondo, Kiminori; Sato, Tatsuhiko   ; Watanabe, Yukinobu; Niita, Koji*

Generally, if several-tens MeV electron is dumped into some material, photons with the same energy level are created by bremsstrahlung radiation. And then neutron is generated because of the (g, n) reactions. In current researches, electron energies are getting higher as the high-energy ions are generated. Therefore, when the energy of laser driven accelerated ion exceeds several-tens of MeV, it is impossible to disregard the neutron generation from the (g, n) reactions. Although such a neutron becomes as a background-nose of the ion measurement, a quantitative evaluation has not carried out in the laser-driven ions acceleration experiments yet. We report an evaluation of those neutron properties by using measurement data in the laser-plasma interaction experiments, and it is discussed with a result of Monte Carlo simulation including the (g, n) reaction processes.